Typically, integrated circuits such as memory modules are tested and certified by memory manufacturers to ensure that memory modules operate properly on signals within parameters that are allowed by the appropriate specifications.
Not only are integrated circuits such as memory modules subject to testing to determine whether they meet manufacturer specifications, but they are also typically subjected to other tests such as pattern testing, parametric tests, and behavioral tests.
Functional tests such as pattern testing and parametric testing verify the functionality of integrated circuits. Pattern testing is an organized method of exercising each memory cell to verify its functionality. Parametric tests verify parameters such as power consumption, standby current, leakage current, voltage levels, and access time.
Behavioral tests, also known as application specific tests, verify that integrated circuits, such as memory modules, operate according to specification in an actual use scenario. An example of a behavioral test would be testing a memory module as it would be used in a personal computing environment running a word processing application.
These tests can be used to determine data valid windows for a memory module, the data valid window defining a period of time in which a valid sample can be expected to be taken from a given data bit region of a given data signal.